Are kawasaki syndrome (or kawasaki disease) and heart murmur related?

Occasionally. Kawasaki disease can lead to most commonly a specific rash, fever, swollen lymph nodes, and specific changes to the lips/tongue and hands/feet. However, there are specific changes that can occur in the heart. Occasionally this may lead to a murmur, which is a specific sound of blood flowing through the heart. Most often, though, kawasaki disease causes heart inflammation without a murmur.
See below. The cardiac complication caused by kawasaki is coronary artery aneurysms. There is no association with heart murmurs.